Raw data status filepath removal

Modifications to the raw data object:
 - Added a status to the raw data, to know when the files have been uploaded or they are being uploaded.
 - Added a function to remove all the filepaths associated from the RawData `clear_filepaths`
 - Added a function to remove a filepath from the RawData `remove_filepath`

Adds the needed bits for #548 
This seems very similar to the above function, but works on a single file rather than multiple files.  Perhaps `remove_filepath` should take a queue as an argument (default `None`), and then `clear_filepaths` can create and  build up a queue and execute a bunch of single removals in a single transaction block. I think this is slightly *less* efficient performance-wise, but would reduce code duplication in these two functions.